DirectX9中非2次方尺寸的图片渲染模糊问题的完美解决方案

蓝屏死机

谢谢楼主分享，
不过图片还是以2的N次幂为好。

hyzboy

缩放成2次幂是因为旧显卡只能显示2次幂尺寸的图片,和mipmaps完全无关。

tonykee

我们的游戏用的图片都是2的n次方大小的
不管怎么说，还是谢谢lz分享心得

轩辕崇正

是我奇怪了，多年来，一直以为D3D只能处理2的次方的图片，从未听闻还可以处理非2次方的情况。
即便现在在到网上查阅一翻，仍然通通都是声称要2的次方才行，似乎2的次方已成了一种定律。
就是非常奇怪，为何没有非2次方的加载方法。。这个问题我当初学DX的时候就问过，但所有人都说一定要2的次方，没别的办法，然而我看到很多商业游戏资源，并不是所有图片全是2的次方，比如2D游戏里，单个分割场景的尺寸是320×240，这个就不是2的次方。这个疑问也多年未有人给我个答案。

wsz317sky

mipmap， 没有mipmap的3d game是多么糟糕,

hyzboy

早期的显卡，以及现在的低端显卡需要2次幂尺寸的贴图。为了照顾所有的显卡所以必须这样做。
等再过5年，估计可以放弃。不过游戏机上应该不会，因为2次幂的必境快很多。

这个和D3D,OPENGL无关，只要显卡支持就都支持，反之亦然。

游戏阿家

楼主不会是有"尝试法"一个个改参数试出来的吧~~

songge09

糊涂，还带动这么多人一起糊涂
之所以用2次幂，那是图形sdk考虑到了很多效率的问题和实现某些功能的简洁性，你不去搞清楚这些问题，反而寻找不使用2次幂的可能途径，不知道该怎么说你才好
另外，你把过滤关掉了，为什么要关掉呢，你这样还能缩放旋转吗，还有意义吗

小小C

看下这个网站,上面统计了主流显卡是否支持 D3DPTEXTURECAPS_NONPOW2CONDITIONAL 标志

http://www.kludx.com/capability.php?capability=144

再来看看SDK中关于 D3DPTEXTURECAPS_NONPOW2CONDITIONAL 的解释:

D3DPTEXTURECAPS_NONPOW2CONDITIONAL
D3DPTEXTURECAPS_POW2 is also set, conditionally supports the use of 2D textures with dimensions that are not powers of two. A device that exposes this capability can use such a texture if all of the following requirements are met.

The texture addressing mode for the texture stage is set to D3DTADDRESS_CLAMP.
Texture wrapping for the texture stage is disabled (D3DRS_WRAP n set to 0).
Mipmapping is not in use (use magnification filter only).
Texture formats must not be D3DFMT_DXT1 through D3DFMT_DXT5.
If this flag is not set, and D3DPTEXTURECAPS_POW2 is also not set, then unconditional support is provided for 2D textures with dimensions that are not powers of two.

A texture that is not a power of two cannot be set at a stage that will be read based on a shader computation (such as the bem - ps and texm3x3 - ps instructions in pixel shaders versions 1_0 to 1_3). For example, these textures can be used to store bumps that will be fed into texture reads, but not the environment maps that are used in texbem - ps, texbeml - ps, and texm3x3spec - ps. This means that a texture with dimensions that are not powers of two cannot be addressed or sampled using texture coordinates computed within the shader. This type of operation is known as a dependent read and cannot be performed on these types of textures.


D3DPTEXTURECAPS_POW2
If D3DPTEXTURECAPS_NONPOW2CONDITIONAL is not set, all textures must have widths and heights specified as powers of two. This requirement does not apply to either cube textures or volume textures.

If D3DPTEXTURECAPS_NONPOW2CONDITIONAL is also set, conditionally supports the use of 2D textures with dimensions that are not powers of two. See D3DPTEXTURECAPS_NONPOW2CONDITIONAL description.

If this flag is not set, and D3DPTEXTURECAPS_NONPOW2CONDITIONAL is also not set, then unconditional support is provided for 2D textures with dimensions that are not powers of two.

小小C

再来看看 OpenGL 的

http://www.kludx.com/capability.php?capability=460

OpenGL GL_ARB_texture_non_power_of_two:

http://www.opengl.org/registry/specs/ARB/texture_non_power_of_two.txt